A spirometry (also known as a pulmonary function test or lung function test) is a common and effective diagnostic test to assess lung function. It is a reliable way for the doctor to test the lungs for conditions such as COPD (chronic obstructive pulmonary disease) and asthma.
A doctor or trained medical technician may use spirometry to examine a person who has chronic cough and mucus production, or a history of risk factors for COPD. It can also be used to assess if a treatment or therapy has improved lung function, or if a patient’s condition has worsened.
Spirometry is a painless, noninvasive and effective test. During the test, patient will be asked to take in a big breath, and then blow as hard and long as patient can into a mouthpiece. This will be repeated several times and the test may also be repeated after medication is administered to check if patient has responded to it.
The machine measures how much air patient can blow out from the lungs and how fast patient can blow it out. A spirometry can inform the doctor as to whether patient’s breathing is normal through a number of common measurements, such as:
- Forced Vital Capacity – the largest volume of air that can be blown out
- Forced Expiratory Volume (FEV1) – the volume of air that can be expelled in the first second
Before the test, patients are advised to do the following:
- Do not smoke at least one hour before the test
- Do not drink alcohol within four hours of the test
- Abstain from eating a large meal within two hours of the test
- Wear loose clothing
- Do not perform vigorous exercise within 30 minutes of test
- Consult the doctor as to whether or not patient should abstain from inhaler medications prior to the test